restoring dual boot

I got a key logger or steam stealer on my main partition so i made a separate partition and installed win 7 on it so i could play without worrying about my steam account getting stolen (again) since the file was FUD. i used to have a dual boot setup but now its gone so i automatically get booted into the separate partition with no option to boot into the main partition. Is there a way to restore the dual boot option?

There is a way, but don't do it. I took the step that way and fucked up my main partition and i got stuck in an ever lasting reboot. It has something to do with a corrupted/deleted bootmtr or something like that.

My MBR was fucked when I wanted to switch my secondary partition to my primary. One had windows XP and the second one had windows 7. So i wiped out he xp partition and set my windows 7 as primary. But for some reason something got fucked and the mbr was on the primary and windows 7 couldnt find it or something like that.

Took me 3 hours to fix since i was googling my ass off. I had to save my 10tb of pr0n.

Here is something that may amuse you in this particular situation. I had no idea until approx. 1 month ago, (i was reformatting hard-drive and wanted a 100% clean slate, also installing Windows 7) what a partition was for a comupter and how you could use it for your OS. Now I get the jist of it, but frankly, choose not to add to the complication of computer whatever stuff.